HPV is one of the most mysterious sexually transmitted infections (STI). What is HPV? Although 80 million Americans are infected with human papilloma virus, many folks don't even know that they have it. That's right, the most common STI in the country often doesn't even have symptoms. And in 90 percent of infected cases (in otherwise healthy individuals) the immune system will clear the virus from the body within two years.

A recent study from the National Center for Health Statistics further shows just how prevalent it is, revealing that 42 percent of Americans ages 18 to 59 have HPV. Of that population, roughly 25 percent of men and 20 percent of women are infected with high-risk strains, which are most commonly linked with cervical cancer.

While these new findings shouldn’t necessarily alarm you, the prevalence of the virus — and the significant number of high-risk cases — is reason enough to get educated and make sure you’re getting screened regularly.

Dr. Grace Lau, assistant professor of obstetrics and gynecology at NYU Langone Medical Center, helped walk us through the most need-to-know aspects of the most under-the-radar STI.

What is HPV?

HPV is a sexually transmitted virus with over 100 types, or strains, 40 of which are sexually transmitted via oral, vaginal and anal sex. (Other strains cause hand and feet warts, and while those might look scary, they're otherwise benign). Although the virus doesn’t manifest any visible symptoms, except in the case of genital warts, it's extremely contagious, with any sexually active person susceptible to it, according to the CDC. Unlike with other STI's, wearing a condom doesn’t fully protect you, as exposed skin surrounding the condom can still spread it, Dr. Lau notes.

High-risk vs. low-risk HPV

The myriad strains of the virus are categorized “high-risk” and “low-risk,” indicating how likely they are to develop into cervical cancer. The strains HPV-16 and HPV-18 are responsible for 70 percent of cases of cervical cancer, whereas strains HPV-6 and HPV-11, while linked to 90 percent of cases of genital warts, have a much lower likelihood of causing cancer.

Who is at risk?

While any sexually active person can develop HPV, the report from the National Center for Health Statistics found that the prevalence of both oral and genital cases of infection was highest among non-hispanic black adults and lowest among non-hispanic Asians.

The American Cancer Society presents statistics on who is more likely to develop cervical cancer, listing smokers, folks with weakened immune systems and people infected with chlamydia among the higher-risk population.

How do you get tested for it?

It depends on your age and sex. Guidelines from the American Society for Colposcopy and Cervical Pathology advise that women in their twenties get pap smears every three years, and from age 30 to 65, every five years. While twenty-something women are not specifically tested for HPV, the pap smears can detect abnormal cervical cells, after which your doctor can assess next steps. Women age 30 and older receive an HPV test in conjunction with the pap smear, which will test for fourteen of the most common high-risk strains.

Not-so-fun fact: Although men are just as likely to contract HPV as women — and just as likely to pass it to a sexual partner — there is no HPV test for men. This is because statistics of men developing anal, penile or oropharyngeal (throat) cancers from HPV are extremely low. According to Dr. Lau, with increased research on HPV, testing for men might — and should — become an option. “[For men] knowing your status and whether this is something you could transmit to your sexual partner could be helpful,” she says.

How do you prevent it?

The best way to prevent HPV is to get vaccinated against it at a young age. The three FDA-approved vaccines approved for females ages 9 to 26 — Gardasil, Gardasil-9 and Cervarix — prevent infections caused by HPV-16 and HPV-18, the high-risk strains that have been linked to 70 percent of cervical cancer cases. While the vaccines may provide some preventative benefit in adults older than 26 — although insurance is less likely to cover it — they are most effective when administered to kids around age 11 or 12, before they’re sexually active and are less likely to have been exposed to the virus.

Dr. Lau notes that the vaccines don’t protect against all the high-risk strains linked to cancer. “As more studies come out, I think we’ll be developing more vaccines that are going to be able to cover a lot more than these strains,” she says.

How do you treat it?

While most incidences of HPV clear up on their own, for persistent cases there are a few options. Genital warts are often treated with prescription gels or removal via cryotherapy (freezing) electrocauterization (burning) lasers or surgery.

In the case of an abnormal pap smear or detection of high-risk HPV, a patient is advised to return for a colposcopy, a procedure that examines the cervix and then biopsies tissue to evaluate any potential precancerous changes in the cells. This can follow with a LEEP procedure — loop electrosurgical excision procedure — which removes the abnormal cells and is 90 percent effective, according to Planned Parenthood.

What you can do:

Aside from getting screened regularly and keeping abreast of new research on the infection, you likely don’t need to spend much time fretting over HPV. “You have to live your life,” says Dr. Lau. “Because the reality is HPV is prevalent, but being educated about what that means and following through with your doctor to make sure if you have an infection it clears is the most important thing.”